I would like to find out more about the ppk I inherited from my grandfather. The serial # is 890460, it has no markings above the "walther" banner, ion the left side it says "waffenfabrik walther zella mehlis (Thur)", model ppk, walther patent cat 765xx?. It has brown palstic handles and a plastic "extension" on the clip. It is still in the original holster w/ an extra clip. Would appreciate anyone telling me something about it and its' value if any.